Abstract
In order to clarify the relationship between magnetite grade and reflectance spectra, spectral testing of different grades of magnetite was carried out to analyze the effect of iron grade on the reflectance spectra of specimens. The results show that the fluctuation trends of the spectral curves of different grades of magnetite are slightly different. By screening the characteristic bands of magnetite grade, it was found that the characteristic bands of different grades of magnetite are mainly distributed in the range of 350-1000 nm and 1800-2500 nm. Then based on the relationship between magnetite grade and reflectance spectra, two inversion models of magnetite grade, PLSR(Partial Least Squares Regression) and MLSR(Multiple Linear Stepwise Regression), were established. By comparing and analyzing the inversion models of magnetite grade established by PLSR and MLSR, it was found that the inversion accuracy based on the PLSR model was better than that of the MLSR model, in which the [Formula: see text] and the RMSE of validation set of the best model was respectively 0.9982 and 0.95%.